SubNamespace should be compatible with kstatus

[erikgb]

What

We use FluxCD to provision our clusters, and FluxCD supports health checks for CRDs compatible with kstatus. And I believe ArgoCD also does this.

It would be nice if the SubNamespace CRD had a status subresource compatible with kstatus. You can read more details in the specification, but I would suggest the following requirements (at least as a start):

• A SubNamespace with empty status has not yet been picked up by the controller
• The controller should ensure .status.obeservedGeneration is equal to .metadata.generation when reconciling a SubNamespace
• If the actual state differs from the desired state, the controller should add status conditions indicating that a reconcile is in progress
• When the actual state equals the desired status, the controller should remove all status conditions
• If the controller is unable to reconcile successfully for any reason, like in a conflict situation, the controller should add conditions indicating what's wrong.

Since the status field on SubNamespace currently is a simple string, this will be a breaking change of status.

How

Describe how to address the issue.

Checklist

• Finish implementation of the issue
• Test all functions
• Have enough logs to trace activities
• Notify developers of necessary actions

[zeroalphat]

@erikgb
Thanks for your feedback.
We will investigate it.

[ymmt2005]

To address this, we need to make an incompatible change to the API.
I mean, we need to cut v2.